1. Field of the Invention
The present invention relates to an optical signal processing device for processing optical signals in the field of optical communications.
2. Description of the Background Art
Due to the explosive development of the Internet, there is a major shift in the mainstream of communications from speeches to data. In near future, the majority of signals transmitted through communication paths are expected to become data packets. In conjunction with this change, there is a demand for an evolution of the optical fiber communication system from a simple large capacity communication path to an intelligent network that can process optical signal packets. An optical router that can distribute optical signal packets according to information on a destination of each optical signal is a key constituent element of such a next generation optical communication network.
The most important element in the optical router is a signal processing device for reading information on a destination or the like from the optical signal. Conventionally, this reading of the destination information has been realized by an electronic circuit.
FIG. 11 shows a conceptual configuration of a conventional device for reading the destination information. As shown in FIG. 11, the optical signals (address information, data, etc.) from an optical fiber communication path are separated by an optical tap 110, and converted into electric signals at an opto-electric conversion circuit 111. These converted electric signals are lead to an electric circuit 112 where the destination information is extracted from the data. The optical signals are then processed according to the extracted destination information, by an optical router 113, for example.
However, the conventional signal processing device requires the conversion of the optical signals into the electric signals before the processing at the electric circuit so that there has been a problem that the processing speed of the signal processing device as a whole is limited by the speed of the electric circuit.
The communication capacity required for the optical communication network has been increasing exponentially since the advent of the Internet, but it is impossible to construct an optical communication system of an ultra high speed such as 40 Gbps or 100 Gbps that will be required in the next or next next generation, by the conventional method for carrying out the processing by converting the optical signals into the electric signals.